Propulsion unit for boats



E. K. SCHULZ PROPULSION UNIT FOR BOATS Oct. l, 1963 4 Sheets-Sheet l Filed Jan. 5, 1962 ,4v-famine.

Oct. 1, 1963 E. K. scHULz PROPULSION UNIT FOR BOATS 4 Sheets-Sheet 2 Filed Jan. 3, 1962 Oct. 1, 1963 E. K. scHULz 3,105,353

PROPULSION UNIT FOR BOATS Filed Jan. 3, 1962 4 Sheets-Sheet 3 62 j .Z All "n l 'I j? Je' ao' @f 'I ffy- Oct. 1, 1963 E. K. scHuLz 3,105,353

PROPULSILON UNIT FOR BOATS mea Jan. s, 1962 4.` sheets-sheet 4 INVENTOR. [aaa/v5 K Sc//u LZ,

BY afs/L) n.5 i L United States Patent O 3,195,353 PB @IUIISIN UNIT FR BGATS Eugene K. Schulz, 23 S. State St., Danville, lll. Filed San. 3, 1962, Ser. No. l64,09 l2 Claims. ("l eli-35.54)

This invention relates to a propulsion unit for boats, and more particularly to a unit for propelling a boat by a jetted llow of water.

It is an object of my invention to provide a propulsion unit for boats which can be driven by conventional inboard and outboard motors, which need not project below the plane of the bottom of the boat with which it is used, which can be easily manipulated for steering said boat, which can be easily manipulated for reversing the direction in which the 'boat is propelled, and which will prove durable and eiiicient in its operation. It is still a further object of my invention to provide a propulsion unit for a boat which will supply coolant to an engine driving said unit, and which will provide a discharge passage for the exhaust gases emanating from said engine.

In accordance with one form of my invention in which it is used in association with, and driven by, a conventional outboard motor, there is provided a housing connected to said motor at the lower end thereof and having a chamber in open communication with a water inlet in the bottom of said housing and a discharge outlet adjacent the rear of said housing. An impeller is carried in said chamber above the inlet and is connected to the drive shaft of said motor for rotation therewith. Upon rotation of said impeller, water is pulled into the chamber through said inlet and is discharged under pressure through said discharge outlet in a jetted ow for propelling the boat to which the motor is connected in a direction opposite to the direction in which the water is jetted out said discharge outlet. Conveniently, the housing may be provided with a liirst passage extending between said chamber and a coolant line leading to the motor for supplying said motor with a portion of the water brought into said chamber. A second passage may also be provided in said housing with one of its ends operatively connected to the exhaust gas passage of said motor and its opposite end terminating adjacent said water discharge outlet for discharging the exhaust gases emanating from said engine at the rear of the housing.

Conveniently, to reverse the direction in which the boat is propelled, I provide a cup operatively connected to the housing and adjustably movable between a position in which it is out of the line of the jetted iiow of water through the discharge outlet so that the boat is propelled forwardly, and positions in which it is in said line of flow so that the water jetted out the discharge outlet is reflected from said cup to propel the boat in a reverse direction, or to idle the boat in a stationary position.

Other objects and features of my invention will become apparent from the more detailed description which follows and from the accompanying drawings, in which:

FIG. l is a fragmentary side elevation of a boat having an outboard motor mounted thereon with a propulsion unit embodying my invention mounted on said motor;

FIG. 2 is an enlarged vertical section of the propulsion unit shown in FIG. l and taken on the line 2 2 of FIG. 3, but showing the reversing mechanism in diierent positions of adjustment;

FIG. 3 is a horizontal section taken on the line 3 3 of FIG. 2;

FIG. 4 is a vertical section taken on the line 4 4 of FIG. 5, and showing a modiiied form of my propulsion unit employing a mixed-dow impeller;

FIG. 5 is a horizontal section taken on the line 5 5 of FIG. 4;

FIG. 6 is a fragmentary longitudinal section of a boat having an inboard motor used in association with a modied form of my propulsion unit;

FIG. 7 is an enlarged fragmentary vertical section of the propulsion unit shown in FIG. 6, `and taken on the line 7 '7 of FIG. 8;

FIG. S is a horizontal section taken on the line 8 8 of FIG. 7;

FIG. `9 is a rear elevation of the boat and propulsion unit shown in FIG. 6; and

FIG. lO is au enlarged vertical section showing a modifled fonm of the linkage for moving the reversing mechanism.

As shown in FIG. l, my propulsion unit is mountable on the lower extension lli of a conventional outboard motor 12 swingably mounted on the transom 14 of a boat 16. As shown, the propulsion unit does not project any farther below the water line 17 than the botom of the boat 16.

My propulsion unit comprises a housing 13 connected to the lower motor extension le, as by bolts 2l, and having a bottom plate 22 secured to its lower face as by bolts 23. As shown in FIG. l, the major portion of the bottom plate 22 is generally coplanar with the bottom of the boat i6, but the forward end of said plate is curved upwardly, as at 25, to direct the water immediately rearwardly of the boat rearwardly below said plate. A pair of laterally spaced, parallel keels 26 project downwardly from the bottom plate 22 and terminate at the rear of the housing. Conveniently, each of said keels is provided with a passage 27, one end of which terminates at the rear of the keel and the other end of which terminates in the plane of the upper face of the `bottom plate.

As shown in FIGS. 2 and 3, the housing i8 is provided with a generally cylindrioally shaped chamber 28 in open communication with an inlet opening 30 formed in the bottom plate 22 and covered by a screen 31. As shown, the major portion of the opening 30 lies generally4 forwardly of the keels 26 so that said keels will not dam the iiow of water to said opening when the boat 16 is turning. Projecting generally tangentially from the chamber 28 is a constricted discharge passage 32 terminating in a discharge outlet 34 disposed adjacent the rear of the housing 1S. Conveniently, the housing IS is further provided with an exhaust passage 36 disposed. around la portion of the chamber 28 with one end of said passage being in open communication with an exhaust gas duct 37 formed in the lower motor extension l@ and the opposite end of said passage being in open communication with the passages 27 in the keels 26. In this manner, the exhaust gases from the motor are conducted through the motor extension 1? for discharge at the rear of the housing below the water line 17. Conveniently, the housing 1S may also be provided with a passage 38 extending between the chamber 28 and a coolant passage 39 in the lower motor extension for supplying coolant to the motor 12.

The propulsion unit is driven by the vertically extending drive shaft 4d on the motor l2. As shown in FIG. 2, the drive shaft 46 extends downwardly into the housing i8, and is journaled in bearings 4retained in said housing by a. grease seal 43 and a snap ring 44. A pai-r of washers 45 are dispo-sed around the `drive` shaft 4d immediately above the chamber 2S to seal the bearings 42 from the pressurized water in said chamber. The shouldered lower end of the drive shaft 49 projects into the chamber 28 and is connected to the hub 47 of a radial dow impeller 48 having an axis of rotation normal to the plane of the inlet opening 3G and parallel with the plane of the discharge outlet 34. It will thus be apparent that upon rotation of the impeller 4S by the drive shaft 4@ water is pulled into the chamber 2S through the opening 3), and is then forced outwardly through the discharge passage 32 and outlet 34 in a jetted ow to propel the boat 16. The natural upward pressure of the water at the rear of the boat created by the boat moving through the water causes said water to be forced upwardly into the inlet opening Sil. With my propulsion unit connected to an outboard motor l2, the motor l2 may be sv g laterally relative to the longitudinal axis of said boat, whereby the jet of water out discharge outlet 34 is adjustable relative to said longitudinal axis of the boat lo to eiect steering thereof.

In order to propel the boat i6 in a reverse direction (to the left in FIG. l) `and to permit it to idle in a stationary position while still discharging a jet of water, I provide a cup 49 having a generally':semi-cylindrical shaped lower portion Sti and vertically swingable in Vlongitudinally extending openings 51 formed in the housing rearwardly of the discharge outlet 34. The cup is swingably mounted on the housing by a pin 52 iixedly carried in a pair of forwardly projecting cup iingers 53 and proj ecting laterally therefrom for reception in a pair of longitudinally extending slots 54 formed in the housing i3. As shown, the cup 49 is urged forwardly to dispose the pin 52 at the forward ends of the slots 54 by a spring 55 interconnected between said cup and housing. A pair of upwardly projecting larms 56 on the cup are interconnected by a cross pin 58 swingably connected to one end of a link 59, with the opposite end of the link 59 being swingably connected to a second link 6d swingably mounted on the housing I, as at 61. The link 6i? is swingably connected to a stud 62 which is connected through a luniversal joint 64 to an oiset vertical control rod 65. The opposite or upper end or" the control rod 65 is connected through a universal joint 66 to the conventional forward and reverse shift lever 67 on the motor 12. Conveniently, the length `of control rod 65 may be adjusted by a turn-buckle 68 to allow for the diierent positioning of the shift lever 57 on diiierent makes and models of motors.

TheV operation of the cup may be described as follows. With the cup in its retracted position shown in FIG. l, it is disposed out of the path of the jetted flow of water through the passage 32 and the boat 16 will be propelled forwardly. Upon movement ofV the shift lever 67 into a reverse position, the control rod 65 is moved downwardly to cause the links 59 and 612i to swing the cup in downwardly about the pin 52 until it yis disposed in the path of the water jet as shown in full lines in FIG. 2. In this position the water jet forces the cup rearwardly against the action of the spring 55 until a transversely extending nose 6% on the rear face of the cup engages a pair of bosses 71 on the housing, as shown in dotted lines in FIG. 2. The jet llow retains the cup in engagement with the bosses 71 so that the `water will be deflected lforwardly from the lower cup portion i) under the propulsion unit to drive the boat in a reverse direction.

To change the positioning of the cup 49, the motor is slowed down to reduce the jet flow through the passage 32, and the cup is then moved forwardly by the spring 55 into the full line position shown in FIG. 2. From this position the shift lever 67 can be moved to an idle position to cause the control arm 65 acting through the links 59 and 6d to move the cup 49 into the tilted position shown in chain link lines in FIG. 2, whereby upon the `'application of additional power to the impeller 48, the jet flow out the discharge passage 32 will cause the cup nose to engage a second pair of bosses 72 above and to the rear of the bosses 7l. In such position, the jet flow will be deflected downwardly from the lower cup portion 5@ and the boat will idle in a stationary position.

To swing the cup 49 into the position shown in FIG. l for driving the boat forwardly, it is merely necessary'to slow the impeller 43 so that the spring 55 can overcome the `force of the jet to move the cup forwardly. so that it is free to swing upwardly past the bosses 7l and 72. The cup will then be retained in this retracted position out of the line of the jet iiow through the passage 32 by the shift lever 67.

An alternative embodiment of the propulsion unit shown in FIG. 2 is shown in FIGS. 4 and 5, and comprises a housing i8' connected, las iby bolts 21, to the lower extension lll' :of a conventional outboard motor and having a bottom plate 22 secured to its lower face as by bolts Z3. A pair of keels 26 project downwardly froms aid plate 22 and are provided with passages 27 open at the rear of the housing l.

As shown in FIGS. 4 and 5, the housing 13 has a chamber 2S in open communication at its lower end with an opening 39' formed in the plate 22' forwardly of the keels 26 and covered by a screen 3l. Extending generally tangentially outwardly from the chamber 28 is a constricted discharge passage 32 terminating in a discharge outlet 34. As with the other modification of my invention, an exhaust passage 36 is disposed around a portion of the cham-ber 2S and is in open communication with an exhaust passage 37 in the motor extension itl land the passages 27 in the keels 26'. Further, the housing ld may also be provided with a passage 38 extending between the chamber 2S and a coolant 39 in the lower motor extension.

In the embodiment lshown in FiGS. 4 and 5, the vertically extending drive shaft 4% of an outboard motor extends downwardly through bearings 42', retained in the housing by a grease seal 43 and snap ring 44, and through washers 45', with the lower end of said drive shaft terminating Within the chamber 2S'. The shouldered lower end of the drive shaft 4d carried within the vertical extent oi the chamber 28' is connected to a spacer 74 at the top of the charnber 28 and to the hub 75 of mixed-how impeller 76 at the bottom of said charnber below the spacer 74. As shown, the impeller blades 77 are disposed below the gener-al plane of the discharge passage 32', and are arcuate in both their radial and axial cross-sections to thus lift the Water into the cham-ber 2S through the opening 3d and torce said water out through the discharge passage 32 and discharge outlet 34 in the form of a jet.

The embodiment shown iin FIGS. 4 and 5 diiers from the embodiment shown in FIG. 2 only in the conflguration of the chamber 28' 'and in the use of the mixeddlow impeller. And as shown in FIG. 4, it may employ the same control mechanism shown in FIG. 2 for directing the jet iiow out of the housing 18 for propelling a boat forwardly, rearwardly, or for idling the boat in a Stationary position.

As shown in FIGS. 6 9, my propulsion unit employing either a radial flow impeller as shown in FIG. 2 or a mixed-flow impeller las shown in FIG. 4 may also -be employed in combination with a conventional inboard motor 3l? mounted within a boat 8l. With a portion of Jthe propulsion unit being disposed within the extent of the boat, however, it is necessary to provide `an opening S6 in the bottom of the boat in direct communication with a water inlet in the propulsion unit. In the manner previously described in connection with FiG. 2, the water is drawn into the unit housing 83 and discharged under pressure through the outlet 85 of the discharge passage d2 projecting through the boat transom 84. In the embodiment shown, Iche exhaust from the motor 80 is dis charged through conventional ducts d extending through the transom S4, but, if desired, the housing 83 may be provided with exhaust passages like those shown in FIGS. 2 and 4.

To provide a means for steering the boat 81, a steering assembly shown in FIGS. 7 and 8 is swingably mounted on the end of the housing S3 projecting through the transom 84. As shown, there ,is provided a tube 9i) provided at its forward e-nd with :a pair of forwardly projecting anges 92 interconnected by arcuate side walls 93. The flanges 92 extend over the rounded rear portion of the housing 83 and are swingably connected thereto by a bolt 94 journaled in bearing 95 and received in the lower portion of the housing, and by a pin 96 projecting downwardly from a ibracket 97 mounted on the upper iiange 92 and received in the upper portion of said housing. The bracket 97 is connected to a vertically extending rotatable steering rod 98 journaled in brackets 99 mounted on the transom fand connected fat its upper end to any desired arrangement of steering ca.- bles, whereby the control rod 93 may be rotated for rotating the tube 9i) about the axis of the bolt 94 and pin 95 to cause the water jet from the passage 32 to be discharged at the desired angle with respect to the longitudinal axis of the boat for steering said boat.

The rearward end of the tube 80 is provided with the same construction shown in FIG. 2 for mounting a reversing cup on said tube to reverse the direction in which the propulsion unit will propel the boat 31. To this end, the opposed side walls of the tube 99 are provided with two sets of bosses 71 and 72. The forwardly projecting fingers 53' on the cup 49 are interconnected by a pin 52 slidably and rotatably carried in a pair of longitudinally extending slots 54 formed in the tube side walls, said pin being urged forwardly in said slots by a spring 55 interconnecting the cup and bracket 97. The upwardly extending arms 56 on the cup 49 are interconnected by a pin 5S' swingabiy connected to link 59' which is swingably connected to a second link 69' swingably mounted `on the bracket 97. The link 60 is swingably connected to a stud 62' which is connected through ya universal joint 64 to a vertically extending control rod 65. 'Ihe upper end of the rod 65 is connected through a universal joint 16d ,to 'one end of a crank 101. The vopposite end of said crank is connected to and rotatable with a shartt 192 extending through the transom S4. Said shaft may be rotated in any desired manner to rotate the crank 161 for moving the rod 65 vertically. Upon such vertical movement of the rod 65', the links 59 and 60 will swing the cup 49 to and from its retracted position and :into its various positions of adjustment engaging the bosses 71' and 72 in the manner previously described in connection with the showing of FIG. 2.

It will be apparent that the steering movements of the tu'be 90 about the axis of the bolt 94 and pin 96 will cause the l-inkage 59 and dil' to move relative t-o the control rod 65. However, such movement will be negligible `and the cup 49 will still remain in the desired position of adjustment.

An alternative linkage and control assembly is shown in FIG. l0. In such assembly, the pin 53 interconnecting the arms 56' of the cup 49 is swingably connected to one end of a pivot link 164. 'Ihe opposite end of said link 104 is swingably connected to a bushing 105 mounted on a control rod 105 vertically slidable in an extension 107 mounted von one of the brackets 99 for the steering rod 98. rllhe .bushing 105 is rotatably mounted on the rod 1636 by pairs of lock nuts 108.

The rod 106 is ventically movable in any convenient manner, such as by having its upper end joined to a bracket 109 swingably connected to one end of la crank 191 having its opposite end connected to a shaft 110 journaled in a sleeve 111 extending through the boat transom. The end of the shaft 116 opposite the crank 101' is connected to a second crank 112 which may be swung in any convenient manner to cause the shaft 110 to swing the crank 101 and eiiect a vertical movement of the rod 196. Thus, upon raising said rod to dispose the bushing .105 in fthe position shown in full lines in FIG. l0, the link 164 will swing the cup 49 about its pivot pin 52 into its retracted position for propelling the boat to which the unit is connected forwardly. Con- A versely, movement of the rod 106 downwardly to dispose the bushing 105 in the dotted line position shown in PIG. l0 will pivot the cup 49 into a position in line with the jet flow out of .the housing to force said cup rearwardly into engagement with the lower set of bosses 71 `on the side walls of the :tube whereby the jet dlow will ibe deected Iforwardly under the boat for propelling said boat in a reverse direction. By moving the rod 195 into an intermediate position to dispose the bushing in the position shown in chain link lines in FIG. 10, the cup 49 will also be disposed in the jet now from the housing and will be moved rearwardly to engage the upper set of bosses 72 to deiiect the jet ow downwardly whereby the boat will idle .in a stationary position.

It is to be understood, of course, that the propulsion unit used with the linkage and control assembly shown in FIG. 10 has the same structure and method of operation as that shown in FIGS. 6-9. It is also to be understood that the laterally swingable steering assembly shown in FIGS. 7 and l0 may also be used in association with a propulsion unit vfor an outboard motor where it is desired to mount said motor in a ixed position `on a boat to thus provide a means for steering said boat.

I claim las my invention:

l. A water-propulsion unit for propelling .a boa-t, comprismg (a) a housing operatively connected to said boat and having a chamber in open communication with an inlet yformed in the Ibottom or" said housing and an outlet adjacent the rear of said housing,

(b) the bottom of said housing being formed by a plate secured to the lower end of said housing and having said inlet formed therein,

(c) said plate and housing extending forwardly of said chamber with their forwardly extending ends curved upwardly,

(d) keel means projecting downwardly from said plate rearwardly of the inlet formed therein,

(e) an impeller carried in said chamber above said inlet and having an `axis of rotation generally normal to the plane of said inlet Iand parallel with the plane of said outlet,

(f) drive means for rotating said impeller to pull water into said chamber through said inlet 4for discharge through said outlet,

(g) a constricted pass-age interconnecting said cham- Yber and outlet whereby said water is forced out of said outlet under pressure for propelling said boat,

(h) a cup having a genenally semi-cylindrically shaped lower portion and operatively connected to said housing for movement between a retracted position in which said lower portion is out of the line of flow of 'water through said outlet and the boat is propelled forwardly and a lowered position Iin lwhich said lower portion is in the line of flow and the water is reliected therefrom to propel the boat rearwardly, and

y(i) means for moving said cup between its retracted position an-d said lowered position.

2. A water-propulsion unit as set forth in claim 1 in which |(a) said impeller is a mixed flow impeller mounted on said drive means adjacent the bottom of said chamber,

(b) a spacer is carried on said drive mea-ns between said impeller and the top of said chamber, and

(c) said chamber is disposed in open communication with said outlet by a discharge passage extending generally tangentially rearwardly from said chamber above the plane of said impeller.

3. A water-propulsion unit yas set forth in claim 1 with the addition that (a) said cup is connected to said housing by a pivot pin swingably mounting said cup on said housing for ver-tical .swinging movement through an opening in said housing rearwardly of said outlet, and

(b) means yare provided `on said housing engageable with said cup for releasably locking said cup in said lowered position.

4. A water-propulsion unit for propelling a boat, comprising (a) :a housing operatively connected to said boat and having a chamber in open communi-cation with an inlet formed in the bottom of said housing and an outlet adjacent the rear of said housing,

(b) an impeller carried in said chamber above said inlet and having .an axis of rotation generally nor- Imal to the plane of said inlet and parallel with the plane of said outlet,

(c) drive means for rotating said impeller to pull water into said chamber through said inlet for discharge through said outlet,

(d) a constricted passage interconnecting said chamber and outlet whereby said water is vforced out of said outlet under pressure for propelling said boat,

(e) a cup having a generally semi-cylind-rically shaped lower portion and swingably connected to said housing by a pivot pin carried in a pair of longitudinally extending slots formed in said housing for vertical swinging movement of said cup between a retracted position in which said lower portion is out of the line of flow o water through said outlet and the -boat is propelled forwardly and a lowered position in which said .lower portion projects through an opening in said housing rearwardly of said outlet in said Iline of iiow and the water is reflected therefrom to propel the boat rearwardly,

(j) a pair of bosses on said housing disposed rearfwardly of said cup when said cup is in said lowered position for releasably retaining said cup in its lowered position,

(g) ya spring connected between said cup and housing to urge said pivot pin forwardly in said slots whereby said cup can swing past said bosses into its retracted position, and

(h) means for moving said cup between its retracted position and said lowered position.

5. A water-propulsion unit as set forth in claim 4 with the addition that (a) a second pair of bosses are disposed on said housing to the rear `and above said other bosses for releasably engaging said lower cup portion and retaining the same at an angle to the line of ow of water out said outlet for deflecting said water downwardly to idle the boat in a stationary position.

6. A water-propulsion unit as set forth in claim 4 with the addition that (a) said means for moving said cup between its retracted `and lowered positions comprise a first link swingably connected to said housing and to a second -linlr swingably interconnected to a pair of upwardly projecting arms on said cup, and

(b) a vertically movable control lrod is swingably interconnected to said first link, whereby upward movement of said rod will cause -said links to swing said |cup into its retracted position and downward movenient of said rod will cause said links to swing said cup into said line of flow of water out the housing outlet.

7. A water-propulsion unit for propelling a boat, compris-ing (a) -a housing operatively connected to said boat and having a `chamber in `open communication with an inlet formed in the bottom yof said housing and a discharge passage extending generally tangentially of said chamber and terminating in an outlet adjacent the rear of said housing.

(b) an impeller carried in said chamber above said inlet and having an axis of rotation generally normal to the plane of said inlet and parallel with the plane :of said outlet,

(c) `drive means for rotating said impeller to pull water into said chamber for discharge through said discharge passage and outlet for propelling said boat,

(d) Ian exhaust passage in said housing for conducting the exhaust gases away from said drive means,

(e) a .pair of laterally spaced, parallel keels projecting downwardly below -said housing and each having Van lopen ended passage disposed in open communication with said exhaust passage,

(f) a cup pivotally connected to said housing and movable through a slot therein between a position in which `it is out of the line of flow of water through said loutlet and the boat is propelled in one direction and a position in which it is in said line of flow and the water is reected from said cup to propel the boat in an opposite direction, and

(g) imeans for controlling the lateral direction in which said water is forced from the housing relative to said boat for steering said boat.

8. A water-propulsion unit for propelling a boat, comprising in combination with an inboard motor mounted in said boat (a) a housing operatively connected to said motor and having a chamber in open communication with an inlet formed in the bottom of said housing `and an outlet adjacent the rear of said housing,

(b) said inlet being in communication with an opening in the bottom of the boat,

(c) an impeller carried in said chamber and connected to the drive shaft of said motor for rotation about an axis generally normal to the plane of said inlet and parallel with the plane of said outlet to pull water into said chamber through said inlet for discharge through said outlet,

(d) a constricted passage interconnecting said chamber and outlet whereby said water is forced out of said outlet under pressure for propelling said boat,

`(e) a tube mounted on said housing rearwardly of said outlet and horizontally swingable with respect to said housing for controlling the lateral direction at which said -water is forced out of said unit relative to said boat,

(f) a Cup having a generally semi-cylindrically shaped lower portion and swingably connected to said tube on a transverse pivot pin for movement through an opening in said tube between a retracted position in which said lower portion is out of the line of flow of water through said outlet and tube and said boat is propelled forwardly and a lowered position in which said lower portion is in said line of ow and the water is reflected generally forwardly therefrom to propel said boat rearwardly, and

(g) means for moving said cup between said retracted and lower positions.

9. A water-propulsion unit as set the addition that (a) the rear portion of said housing projects rearwardly through the transom of the boat and a rounded configuration,

(b) the forward portion of said tube comprises laterally projecting upper and lower walls interconnected by a pair of arcuate side walls and swingably connected to said rear housing portion, and

(c) a vertically extending rotatable steering `rod is connected to said upper ilange for swinging said tube laterally to direct the line of iiow of water out said outlet tube relative to the longitudinal axis of said boat.

10. A water-propulsion unit as set forth in claim 8 with the addition that l (a) said pivot pin is longitudinally slidable in a pair of slots formed in the side walls of said tube,

(b) a pair of bosses are disposed on said tube rear- Yforni in cnam s with wardly of said cup for engagement therewith when said cup is in its lowered position,

(c) a spring is connected between said cup and housing to vurge said pivot pin forwardly in said slots whereby said cup can swing forwardly past said bosses into its retracted position, and

(d) said means for moving the cup comprises a pivot linkage connected to said cup and a vertically movable control rod, whereby upon vertical movement of said rod said linkage vill swing said cup about the axis of said pin.

11. A water-propulsion unit as set forth in claim 10 in which (a) said pivot linkage comprises a rst link swingably connected at one of its ends to said cup and at its opposite end to a second link swingably mounted on said tube, and

(b) said control rod is pivotally interconnected to said second link.

1G 12. A water-propulsion unit as set forth in claim 10 in which (a) said pivot linkage comprises a link swingaoly connected at one of its ends to said cup and at its opposite end to a bushing mounted on said control rod for vertical movement therewith, and

(b) said rod is vertically slidable in 1bracket members mounted on the rear of said boat and said bushing being rotatable about said rod.

References Qited in the le of this patent UNlTED STATES PATENTS 2,743,698 Leonard May 1, 1956 3,035,409 Pifer May 22, 1962 3,944,259 Tuttle uly 17, 1962 3,046,735 Burgin July 31, 1962 3,054,375 Neely Sept. 18, 1962 

1. A WATER-PROPULSION UNIT FOR PROPELLING A BOAT, COMPRISING (A) A HOUSING OPERATIVELY CONNECTED TOI SAID BOAT AND HAVING A CHAMBER IN OPEN COMMUNICATION WITH AN INLET FORMED IN THE BOTTOM OF SAID HOUISING AND AN OUTLET ADJACENT THE REAR OF SAID HOUSING, (B) THE BOTTOM OF SAID HOUSING BEING FORMED BY A PLATE SECURED TO THE LOWER END OF SAID HOUSING AND HAVING SAID INLET FORMED THEREIN, (C) SAID PLATE AND HOUSING EXTENDING FORWARDLY OF SAID CHAMBER WITH THEIR FORWARDLY EXTENDING ENDS CURVED UPWARDLY, (D) KEEL MEANS PROJECTING DOWNWARDLY FROM SAID PLATE REARWARDLY OF THE INLET FORMED THEREIN, (E) AN IMPELLER CARRIED IN SAID CHAMBER ABOVE SAID INLET AND HAVING AN AXIS OF ROTATION GENERALLY NORMAL TO THE PLANE OF SAID INLET AND PARALLEL WITH THE PLANE OF SAID OUTLET, (F) DRIVE MEANS FOR ROTATING SAID IMPELLER TO PULL WATER INTO SAID CHAMBER THROGH SAID INLET FOR DISCHARGE THROUGH SAID OUTLET, (G) A CONSTRICTED PASSAGE INTERCONNECTING SAID CHAMBER AND OUTLET WHEREBY SAID WATER IS FORCED OUT OF SAID OUTLET UNDER PRESSURE FOR PROPELLING SAID BOAT, (H) A CUP HAVING A GENERALLY SEMI-CYLINDRICALLY SHAPED LOWER PORTION AND OPERATIVELY CONNECTED TO SAID HOUSING FOR MOVEMENT BETWEEN A RETRACTED POSITION IN WHICH SAID LOWER PORTION IS OUT OF THE LINE OF FLOW OF WATER THROUGH SAID OUTLET AND THE BOAT IS PROPELLED FORWARDLY AND A LOWERED POSITION IN WHICH SAID LOWER PORTION IS IN THE LINE OF FLOW AND THE WATER IS REFLECTED THEREFROM TO PROPEL THE BOAT REARWARDLY, AND (I) MEANS FOR MOVING SAID CUP BETWEEN ITS RETRACTED POSITION AND SAID LOWERED POSITION. 